Since our last article checking if Print Shield alters the colors, our test sheets have been hanging outdoors, tacked to the side of my toolshed, exposed to both direct and indirect sunlight as well as indirect rain (they are under a small awning) and temperature/humidity changes.
The tl;dr (too long, didn't read) is:
No significant change in either the coated or uncoated yet. Will check again in another month and a half.
Tell me a lot more....
I was actually surprised that there has been no discernable change to the uncoated, measurements against the first test are all with in margin of error, especially considering...
Since our first article on Print Shield we have upgraded our aging i1 Pro 2 to a brand new i1 Pro 3, this likely gets more consistent reads which accounts for the lower delta-e values compared to our original tests.
Its possible that the exposure to the sunlight and elements brought the coated and uncoated closer together, but I think a more consistent measurement tool is a more likely explanation. We will be doing more tests on this and similar products in the near future that should help definitively answer that question.
Its also worth noting that neither test sheets yet show signs of wear or mold on the front or on the reverse.
Below are the patch measurements, with the uncoated in black on the left, and the ones coated with Print Shield in red on the right. Note the delta E values on the far right under the box that says CIEDE2000 all indicate that there is no perceivable difference between the two.
Looking forward to checking these after another six weeks to see if anything has changed!
If you purchase Print Shield from Red River Paper using this button, we get a small sales commission in the form of store credit with Red River - that helps a lot with us being able to purchase the materials to do all this independent testing. This article was not otherwise sponsored and we paid for all materials and time associated with it.
LL, aa, bb <- you can compare the numbers you see before each graph to the L*a*b* numbers in the graph screenshot to get a sense of how close they are to what was in the original file we printed.
Higher L values means lighter and lower means darker.
Higher a values means more magenta, lower means more green
Higher b values means more yellow, lower means more blue
So for example in this first one, the printed swatches are slightly darker, very slightly more green, and very very slightly more blue than what is in the original image file for the Quick Evaluation Worksheet - which is now available as a free download.
70, -24, 60
42, 54, 26
50, 0, 0
64, 17, 17
33, 20 -22
15, 0, 0
Note that its expected that prints on Aurora Art Natural are not able to hit an L value of 15. With the ICC profile we used for these evaluations, around 22 is about the darkest we will get.
80, 3, 84
90, 1, -1